Yes, Poland better be careful who they let in.
Flashback: Massacres of Poles in Volhynia and Eastern Galicia
The killings were directly linked with the policies of the Bandera faction of the Organization of Ukrainian Nationalists and its military arm - Ukrainian Insurgent Army, whose goal specified at the Second Conference of the Stepan Bandera faction of the Organization of Ukrainian Nationalists (OUN-B) during 17–23 February 1943, or at least in March 1943 was to purge all non-Ukrainians from the future Ukrainian state. Not limiting their activities to the purging of Polish civilians, the UPA also wanted to erase all traces of sustained Polish presence in the area.
http://en.wikipedia.org/wiki/Massacres_of_Poles_in_Volhynia_and_Eastern_Galicia